Brush holder assembly



April 10, 195 cs. D. STAPLETON BRUSH HOLDER ASSEMBLY Filed June 17, 1949 Inventor Glenn D. Stapleton by Wfimwe H15 Attorney Patented Apr. 10, 1951 BRUSH HOLDER ASSEMBLY Glenn D. Stapleton, Fort Wayne, Ind., assignor to General Electric Company, a-corporation of New York Application June '17, 1949,'Serial N 0. 99,646

2 Claims. (01. 171-423) Myinvention" relates toholders for current collector contact members and particularly to cartridge type brush holders with longitudinally movable contact members therein.

Inholders for current collector con-tact members,: brush-holders and brush holder assemblies of the type commonly used onsmall electric motors it is desirable to reduce the-cost of the component parts and to expedite and simplify replacement of the parts most subject to wear, namelythe-cont-act members. In previously used cartridge type brush holders, it has been customary' to: employ at least two cooperating screwthreaded parts to hold the end cap in assembled relationship with the-brush holder. These-structures have been satisfactory except that screw threads are relatively expensive to manufacture and the screw threadedfastenings require a time consuming number of revolutions in assembly to bring them into the completely assembled position.

It is therefore an object of my invention to provide a cartridge type brush holder assembly in which screw threaded fastenings are unnecessary.

It is a further object of my invention to provide a simplified low cost brush holder assembly wherein the brush holder cap member need not be rotated more than one quarter of a turn as it is assembled.

It is yet a further object of my invention to provide an improved brush holder assembly wherein the force of a resilient member used to bias the contact member is also used to hold the cap member in assembled relationship within said brush holder assembly.

A still further object of my invention is the provision of a brush holder assembly which will allow faster assembly and disassembly.

In its broad aspects, my invention consists of a cartridge type brush holder assembly wherein the end cap is fastened in place by the use of a bayonet structure and wherein wings on the end cap engage with grooves in the brush holder body by a one-quarter turn of rotation after insertion of the end cap, the end cap being thereafter held in position by a resilient contact biasing member.

Referring to the drawing, Fig. 1 is a side elevational view, partly in section, illustrating the improved brush holder assembly of this invention and Fig. 2 is an exploded view illustrating, in perspective, the various components of this improved brush holder assembly.

Referring now to Fig. 1, there is shown a portion of the stationary frame- I of a 'dynamoelectric'machine having a brush tube-receiving openh1g2 formed therein. A brush holder tube 301 the cartridgety pe 'is inserted'iin a resilient insulating sleeve 4, formed'of any convenient materialaisuc'h. asrubber 'or neoprene, which :in turn is positioned in the opening 2 of the stationary frame, member l. Holder 3, as shown-in Fig. 2, is provided with a longitudinally; extending contact member slot 5 therein whichis of a rectangular cross-section, the linear dimension of twoof the-sides of-the rectangular cross-section being approximately'twice the linear dimension of the other two. Longitudinal grooves 6 are provided in the longest sides of the contact member slot. These grooves are arc-uate in shape in order that the slot may better accommodate a resilient compression coil spring 1 in the completed assembly which is more fully described .below;

A contact member 8 of any suitable material, such asvca rbon, is arranged for longitudinal movement in theaslot Ewandris adapted to be biased longitudinally of the brushl'holder'hy spring 1 towardone-end thereof for contact with a current collector 9,. which; is part of "the rotating armature structure of the dynamoelectric machina Spring 7 is held-in compression by engagement with :the under side of a cap assembly H] which engages the upper end of the holder 3. Cap assembly [0 comprises terminal pin II and wing washer 12 which are riveted together as shown at IS in Fig. 1 to form a unitary end cap structure. These parts are fabricated separately and assembled in this way for reasons of economy. Wing washer I2 is provided with wings [4 which together have an outline similar to the section of contact member 8 so that they fit easily into contact member slot 5 for longitudinal movement therein. Transverse slots [5 are cut into the brush holder 3 extending radially inwardly into grooves 6 and through the longest sides of the rectangular section of contact member slot 5. These transverse slots l5 accommodate win-gs [4 on washer 12 when the cap assembly has been inserted into the contact member slot 5 and rotated. It will be seen that wings l4 contain small ribs or protrusions IS in their upper surfaces. These ribs engage depressions I! provided in the upper edges of transverse slots l5.

Prior to final assembly, a subassembly is made consisting of cap assembly l9, resilient coil spring 1 and contact member 8 held together by a current conductive braided pigtail 18 which is embedded at one end in contact member 8 and firmly conductively connected at the other end to leap assembly Ill by a suitable method such as tionary frame member I The subassembly above described, may then be :inserted into the contact member slot 5, contact member 8 being inserted first. Contact member 8 "is pushed down through the slot until it is biased against current collector 9 and cap I!) is further depressed compressing spring 1 until the wings I4 have entered slot 5 sufficiently to come opposite slots l5, at which time cap I0 is revolved onequarter of a turn and wings M engage the upper walls of slot I5, and ribs [6 of Wings 14 seat in detents I! of slots l5. Cap assembly in is thereafter biased upwardly by spring I, retaining the *cap member firmly in position. Spring 1 therefore serves two purposesbi=asing contact member -3 downwardly and biasing cap member In upwardly to thereby maintain each in the desired position. The interconnection structure between cap member 10 and brush holder tube 3 including the cap member wings l4 and the cooperating brush holder tube slots 85 may be referred to as a bayonet structure.

It will be seen that cap member 10 is adapted to receive means such as terminal screw 13 whereby an electrical connection may be made by an incoming lead wire to said cap member.

While I have described and illustrated a preferred embodiment of my invention, I wish it to be understood that I do not intend to be restricted solely thereto but that I do intend to cover all modifications thereof which would be apparent to one skilled in the art and which come within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a brush holder assembly adapted to be arranged in an opening in the stationary shell of a dynamo-electric machine, a brush holder tube having a longitudinal slot for supporting a brush in contact with the currentcollector 0f the machine, a spring member for biasing the brush toward the current collector, and a cap member having radially extending wings adapted to be inserted axially into said longitudinal slot for compressing said spring member, the outer surface of said cap member being substantially flush with the outer surface of the stationary shell when assembled; the walls of said brush holder having transverse slots communicating with said longitudinal slot at the end thereof adjacent the outer surface of said stationary shell, said radially extending wings adapted to be rotated to engage the transverse slots of the brush holder tube and to be retained therein by the force of said spring member on said cap member.

2. In a brush holder assembly adapted to be arranged in an opening in the stationary shell of a dynamo-electric machine, a brush holder tube having a longitudinal slot for movably supporting a brush in contact with the current collector of said machine, a spring for biasing the brush toward said current collector, and a cap member adapted to be inserted axially into said brush holde tube for compressing said spring, the outer surface of said cap member being substantially flush with the outer surface of said stationary shell when assembled; the walls of said brush holder having a pair of diametrically opposed transverse slots communicating with said longitudinal slot adjacent the outer end of said brush holder, said cap member having a pair of radially extending wings proportioned to enter said longitudinal slot and upon rotation to enter said transverse slots respectively, a detent positioned on the upper wall of each of said transverse slots, and a rib on the upper surface of each of said wings adapted to engage respectively with said detents, said ribs being held in such engagement by the force of said spring on said cap member.

GLENN D. STAPLETON.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Germany Jan. 12, 1911 

